Neuromodular stimulation, including spinal cord stimulation, peripheral nerve stimulation and deep brain stimulation, has been used for the treatment of various ailments including chronic pain. Spinal cord stimulation in particular, has for some time been used to treat cervical radicular pain from the neck to the arms and lumbar radicular pain from the lower back to the legs. During a treatment implementing spinal cord neuromodular stimulation, a lead including current-carrying electrodes is inserted into a patient's spinal canal posterior to the spinal cord, and electric potential is applied to the electrodes to provide electrical stimulation to overpower and obscure pain signals transmitted from an affected area of the body to the spine. This electrical stimulation typically causes the patient to feel a tingling sensation instead of the pain attributable to the patient's particular ailment.
There are two types of leads commonly used for neuromodular stimulation, a percutaneous lead which can be relatively easily inserted through an epidural needle into the spinal canal, and a paddle lead which must be placed in the spinal canal via an invasive surgical procedure. Percutaneous leads include a wire-like elongated body, which while relatively easily inserted, are often instable in the spinal canal and not easily accurately and precisely positioned. Also, percutaneous leads have a relatively narrow stimulation area and do not allow for lateral displacement of electrodes, and therefore, stimulating current typically may only travel longitudinally along the lead, potentially limiting a treatment's therapeutic effects. Two percutaneous leads may be inserted parallel side by side in the spinal canal to provide a wide stimulation area allowing stimulating current to travel between the two leads. However, positioning two percutaneous leads parallel in such a manner is difficult and time consuming. Conversely, paddle leads are typically constructed of a flattened body which may be accurately and precisely positioned in a relatively stable manner. The form of a typical paddle lead allows for a wide stimulation area with lateral displacement of electrodes permitting lateral current flow perpendicular to a longitudinal axis of the paddle lead. However, the invasive procedure required for placing paddle leads may result in significant patient discomfort and extended recovery time. Also, once placed, paddle leads may not be easily removed or adjusted to accommodate patient preference or treatment requirements.
Modified percutaneous leads have been proposed to provide for greater stability during lead placement. However, such modified forms typically suffer from deficiencies in ease of placement, precision and accuracy of placement, safety, usability, and effectiveness.
It would be desirable to provide a medical stimulation lead which may be easily, safely, accurately, precisely, and stably placed within a spinal canal. Once placed in a spinal canal, such medical stimulation lead should be easily removed and adjusted as required to accommodate patient preference or treatment requirements. Such lead should further accommodate a wide stimulation area and lateral displacement of electrodes.